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$210.00 (USA and Canada only)

Availability: In stock
RS-232 to RS-422/485 Converter 120 VAC

Production Specification

RS-232 to RS-422/485 Converter 120 VAC

AC7A and AC7B

Power Requirements

115 VAC ± 10 VAC @ 50-60 Hz
220 VAC ± 20 VAC @ 50-60 Hz

Power Consumption

0.1 amps @ 115 VAC
5 watts (dissipation)

Temperature Range

0 °C to 70 °C
0 to 95% Humidity (non-condensing)

Optical Isolation

4,000 V between RS-232 and RS-422/485

RS-232 Interface

25-pin, DB-25 female connector

RS-422/485 Interface

Screw terminals or 9-pin, DB-9 female connector

Baud Rate

Up to 38,400 baud; 115.2KBd in Rev. L (AC7A)
and later and in Rev. C (AC7B) and later.

RS-232 Distance

Up to 50 feet

RS-422/485 Distance

Up to 5,000 feet at 38,400 baud (3,000 feet at 115,200 baud)


RS-422/485 full duplex over two twisted pairs and a ground.
Additional twisted pairs for RTS and CTS.
Also supports RS-485 2-wire mode. This requires user to
build a custom RS-232 cable.


Transmit, receive, RTS, CTS, and power


PC-Based I/O Overview

This document shows examples of system architecture for PC-based I/O control systems and lists Opto 22 products that work together for PC-based control. System examples include:

  • Ethernet systems using SoftPAC, a software-based programmable automation controller programmed with PAC Control
  • Ethernet systems using the OptoMMP protocol
  • Direct control of I/O using no I/O processor (no brain)
  • Serial control using a brain and the mistic or Optomux protocol
  • High-speed control using the Pamux protocol

AC7A/B Adapter Card Data Sheet

The AC7A/B is a stand-alone adapter card that converts RS-232 serial communication to RS-422/485 serial communication, which is directly compatible with the Optomux family of intelligent brain boards.

AC7A - AC7B Users Guide

This document gives instructions for installing the AC7A/B adapter card in an Optomux network in 4-wire RS-422/485 mode with a PC and how to communicate with equipment other Optomux.

Declaration of Conformity (EMC, LVD, RoHS)

This document is the Manufacturer's Declaration of Conformity for the products listed herein, in accordance with European, international, and/or national standards and regulations.

Opto 22 RoHS 3 Statement of Compliance - Restriction of Hazardous Substances

This document is a statement of compliance with the EU Directive 2015/863/EU, Restriction of Hazardous Substances (RoHS 3). This document lists Opto 22 products that comply with the substance restrictions of the RoHS 3 directive.

CE Declaration: Low Voltage

This document is the Manufacturer's Declaration for the listed products as mentioned in the attachment - to which this confirmation refers - that they are in accordance with the mentioned European, international and/or national standards and regulations.

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